This invention relates to a precision actuator for generating precise motion in a confined area and, more particularly, the invention is concerned with providing a low profile precision actuator suitable for use as an aileron control system for a one-twentieth scale model high performance aircraft in a wind tunnel maneuverability test and design program.
There are many situations which require precise movement in confined spaces. Confined spaces may be defined as a volume which has severe restrictions in one dimension of a volume while the other two dimensions are relatively free from restrictions. Simple dial pointer movements and complicated control actuators are examples where precise motion in a confined space is required.
In an attempt to accomplish precise movement within confined space limits using conventional methods, the results have been inexact and non-repeatable due to the inherent tolerances associated with the joint fits which attach the actuating members together. For example, the ability to "fly" an aircraft model through realistically simulated maneuvers in a wind tunnel requires that motion measurements be produced that agree well with measurements from the real aircraft in flight so that this capability can be applied in the design, development or refinement phases of an aircraft program. It permits the effect of any design changes to be examined quickly at critical points in the maneuvering flight envelope. Several components are integrated into a computer-controlled closed loop which allows banks, turns and stalls in an almost totally "hands-off" operation.
In a one-twentieth scale model of a high performance aircraft which was used in a test run, new wing and tail control surfaces were designed and fabricated for movement similar to that on the actual aircraft. This required the delicate machining of an aileron control system suitable for installation within the quarter-inch thickness of the model wing. The hereinafter disclosed low-profile precision actuator includes delicate parts which were machined from a stainless steel-molybdenum alloy in order to withstand relatively high aerodynamic forces. The aileron control system according to the invention permits the positioning of the aileron at the required angles to duplicate those experienced by aircraft in maneuvering flight.